Self guiding arcuate set electric cable



July 28, 1959 w. E. DlcKlNsoN SELF GUIDING ARCUATE SET ELECTRIC CABLE Filed June 21, 1956 OOOOOOO ArrvR/VEY United States Patent O SELF GUIDING ARCUATE SET ELECTRIC CABLE Wesley E. Dickinson, Santa Clara County, Calif., assiguor to International Business Machines Corporation, New York, N.Y., a corporation of New York Application June 21, 1956, Serial No. 592,787

9 Claims. (Cl. 174-117) The present invention pertains generally to exible electrical cables and relates more particularly to a cable arrangement for making electrical connections between objects movable relative to each other.

In mechanisms wherein electrical connections are made between parts movable with respect to each other, such connections in the past have been made by ordinary wires or the like. In some applications this has proved satisfactory; however, in others wire fatigue or breakage due to continual bending of the wire is a problem. Such a problem arises in an arrangement such as that disclosed in the copending application Serial No. 477,468, filed December 24, 1954, wherein electrical connections are made to a translatable access mechanism which is repeatedly repositioned at new locations.

Thus, it is one of object of the present invention to provide an improved electrical cable.

Another object is to provide a novel cable arrangement for connecting between mechanisms movable relative to each other.

According to the invention, the individual conductors are ma'de very thin, thereby reducing stresses set up therein due to bending, and the physical characteristics necessary for supporting the thin conductors are provided by a tllexible steel tape to which the conductors are affixed.

A further object is to provide an electrical cable where- 2,897,254 Patented July 28, 1959 ice Fig. 3 is a sectional view taken along line 3--3 of Fig. 2. p Fig. 4 is a transverse section of the novel cable.

Referring now to Fig. 1, the cable 10 of the invention connects between a movable carriage 11 and a stationary support member 12. The apparatus |with which the cable 10 is associated is shown solely for the purpose of demonstrating a useful application of the cable, and it will be understood that the utility thereof is not limited to such structure. Returning to the drawing, the carriage [11 is slidably mounted for 'vertical movement along a way 13 and magnetic transducers (not shown) are mounted near one end 14a of an arm 14 supported by the carriage 11 for movement therewith. The carriage 11 is arranged to `dispose the transducers adjacent selected magnetic discs 1S for cooperation therewith. It is necessary, therefore, to make certain electrical connections between the carriage 11 and other structure (not shown) provided for operating the transducers. When the carriage is continually repositioned, as it is in a device of this type where repeated access is to be had to various portions of the discs 15, failure in these connections due in wire fatigue brought about by repeated bending ofthe y 4 ability to follow the moving portion with which it is associated and acts as its ownguide, therefbyv rendering additional guiding structure unnecessary.

Still another feature of the invention is directed to an improved mechanism for connecting the cable described above, which mechanism permits ready assembly and disassembly of the cable therefrom, whereby the cable is easily replaced when necessary.

A further object of the invention, therefore, is to provide an improved cable connecting structure.

Other objects of the invention willk be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the in vention and the best mode which has been contemplated of applying that principle.

In the drawings:

Fig. l is a perspective view of a machine equipped with the cable assembly ofy the present invention.

Fig. 2 is a sectional view taken along line 2-2 of to repeated bending occurs if ordinary wire cable is utilized. (Stresses set up in the wire when the wire is bent cause breakage.) However, if these connections are made in the manner disclosed herein, fatigue problems are greatly lessened.

The cable 10 comprises a flexible steel tape 16 (Fig. 4) which serves as a guide and supporting structure for the actual conductors. The tape 16 is of a type 'which has a se put into it such as is used in steel tape rulers. By using this kind of tape the cable is provided with rigidity and yet is free to bend. The set in the tape gives it rigidity normal to the thin dimension whereby the tape bends only at its lowermost point. This yields good dynamic characteristics in that the tape is maintained clear of moving parts and is guided in the proper manner without provision of additional guiding structure.

Several conductors 17 are carried by the tape 16. The tape is provided with a thin coating of insulating material 18 ailixed to the concave surface thereof and the rvarious conductorsA 17 are arranged thereon in any convenient manner. In the present embodiment a stripI of aluminum foil is bonded to the material 18, the material 18 being suitably bonded to the tape 16, and the foil is then etched by ordinary printed circuit techniques to form the necessary number of conductors 17 which extend longitudinally of the tape. In this way the tape carries the necessary conductors to form a cable which provides connections to the movable carriage.A It shouldbe noted that the conductors comprise very thin strips of foil and that for this reason the stresses set upy therein ydue to bending are low. (This results in reduced fatigue.)v It is possible to make the conductors veryl thin'since mechanical strength required for support is furnished by the tape.

The cable is secured; electrically and mechanically to the carriage 11 (Fig. l) by aterminal connection member 19, a similar member 20 being provided for terminating the cable at the support 12. The Vmembers. 19 and v20 are substantially identical to eachother, and for this composed of a suitable insulating material. The cable is disposed between the guide 23 and the bracket Z2, and several contact pins 26, one for each conductor 17, extend between the pad 25 and the corresponding conductors 17 through holes 27 provided therefor in the guide 23. The pins 26 are formed integrally with corresponding base members 28 which abut the pad 25, and the pins are staggered diagonally of the tape to provide suitable spacing therefor, whereby each pin cooperatesindependently wrth its respective conductor I7. A wire 29 is connected to each base member 28 for use asis necessary. The pad 25 is made resilient to permit substantially equal'pressure to be applied to each pin when nuts 30l are tightened Von their corresponding bolts 21 to press 'the pins into engagement with the conductors'. Thus, each conductor 17 associated with the tape 16 is connected electrically through a corresponding pin 26 to lthewire 29 associated therewith, the wires extending from the member being connected to suitable electronic circuitry for operating the transducers mounted on the carriage and the Wires 29 extending from the member 19 being connected to these transducers. Thus, it will now be clear that suitable electric paths are provided from the wires 29 through the pins associated with the member 20, through the conductors 17 of the tape 16, through pins 26 associated with the member 19 to the Wires Z9 which are connected to the transducers.

While there have been shown and described and pointed out the fundamental novel -features of the invention asapplied to the preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

l. An electrical cable comprising a ilexible steel tape having a transverse arcuate set therein extending longitudinally thereof for providing rigidity thereto normal to the thin dimension thereof, a thin insulating layer .affixed to said tape, and a plurality of spaced tiexible strips of conducting material attached to said insulating layer, said strips extending longitudinally of said tape and being thin in the dimension corresponding to the thin dimension of the tape, whereby stresses set up in said strips when bending said tape are minimized. 2. An electrical cable arrangement comprising a ilexible tape having a transverse arcuate set therein for providing self-guidance thereof in a direction longitudinally of said tape, said set extending longitudinally along said tape, a plurality of thin exible conductors, means including an insulating material bonding said conductors to said tape, said conductors being thereby insulated from each other, said conductors being thin in the dimension corresponding to the thin dimension of said tape, -a plurality of connectors releasably engaged `with said conductors, resilient means lfor urging each of said connectors independently against said conductors, .means for connecting to said connectors, and means for releasing said connectors from engagement with said conductors, whereby said tape may be removed from said connectors.

3. A self-guiding electrical cable assembly for connecting between objects longitudinally movable relative nto each other comprising a ilexible steel tape having a transverse arcuate set extending longitudinally thereof, a thin layer of insulating material bonded to the inner concave side of said tape, and thin flexible conductive members printed on said layer and extending longitudi- Vnally thereof, whereby bending stresses in said conductive .members are minimized.

4. A self-guiding electrical cable assembly for connecting between objects longitudinally movable relative to each other comprising a exible steel tape having a transverse residual curvature extending longitudinally thereof to confine bending of said cable substantially to the direction of the center of curvature of said curve, a thin layer of insulating material bonded to the inner concave side of said tape, and thin flexible conductive members printed on said layer and extending longitudinally thereof, whereby bending stresses in said conductive members are minimized.

5. A self-guiding electrical cable assembly for connecting between objects longitudinally movable relative to each other comprising a flexible steel tape having a transverse arcuate set extending longitudinally thereof to confine bending of said cable substantially to the direction of the center of curvature of said arc, a thin layer of insulating material bonded to one side of said tape, and thin flexible conductive members printed on said layer and extending longitudinally thereof, whereby bending stresses in said conductive members are minimized.

6. A self-guiding electrical cable assembly for connecting between objects longitudinally movable relative to each other comprising a iiexible steel tape having a transverse arcuate set extending longitudinally thereof to conine bending of said cable substantially to the direction of the center of curvature of said arc, a thin layer of insulating material bonded to one side of said tape, and thin flexible conductive members bonded to said layer and extending longitudinally thereof, whereby bending stresses in said conductive members are minimized.

7. An electrical cable comprising a ilexible steel tape having a transverse arcuate set therein extending longitudinally thereof for providing rigidity thereto normal to the thin dimension thereof, a thin insulating layer aiiixed to said tape, a plurality of spaced exible strips of con- ,ducting material attached to said insulating layer, said strips extending longitudinally of said tape and being thin in the dimension corresponding to the thin dimension of the tape to minimize stresses set up in said strips upon bending of said strips, and means lfor connecting to said conductors including a plurality of discrete independently pressure loaded connector pins for releasably engaging said conductors, said pins being movable with respect to each other, each of said pins being in electrical contact with a corresponding one of said conductors, means for urging said pins against their associated conductors, and a resilient, pad interposed between said urging Imeans and said pins Yto individually compensate for variations in said` urging among said pins whereby uniformly rm electrical connections are made between all said pins and their associated conductors.

8. A self-guiding electrical cable assembly for connecting between objects longitudinally movable relative to each other comprising aexible steel tape having a transverse arcuate set extending longitudinally thereof, la thin layer of insulating material 1bonded to the inner concave side of said tape, thin exible conductive members printed on said layer and extending longitudinally thereof to minimize stresses in said conductive members upon bending of said cable, and means for connecting to said conductors including a plurality of discrete independently pressure loaded connector pins for releasably engaging said conductors, said pins being movable with Irespect to each other, each of said pins being in electrical contact ywith a Vcorresponding one of said conductors, means for urging said pins against their associated conductors, and` a resilient pad interposed between said urging means `and said pins to individually compensate for variations in said urging among said pins whereby uniformly rm electrical connections are made between all said pins and their associated conductors.

9. An electrical cable comprising a flexible steel tape having a transverse arcuate set therein extending longitudinally thereof for providing rigidity thereto normal to kthe thin dimension thereof, a thin insulating layer aixed to said tape, and a plurality of spaced llexible conductive members attached to said insulating layerI said conductive members extending longitudinally of said 1,142,282 Stewart Iune 8, 1915 tape and being thin in the dimension corresponding to 2,701,818 Tims Feb. 8, 1955 the thin dimension ofthe tape, whereby stresses set up in 2,703,854 Eisler Mar. 8, 1955 said conductive members when bending said tape are 2,721,312 Grieg et al. Oct. 18, 1955 mmmlzed- 5 FOREIGN PATENTS References Cited in the file of this patent 725,032 Great Britain Mal- 2, 1955 UNITED STATES PATENTS OTHER REFERENCES 243,180 Ware June 21, 1881 Electronics (publication) December 1955, page 313. 

